A bio-inspired approach will be used to design multi-valent surfactants which, based upon molecular recognition, will control the morphology, size distribution and ordered assembly of nanocrystals. A two-fold strategy will be used to form assemblies that have applications in biological imaging and controlled drug delivery. The bottom-up growth of specific crystalline morphologies will be accomplished using molecules designed to both recognize and attach to specific crystallographic faces. The systematic evaluation of a series of additives will produce a better mechanistic understanding of the molecular recognition events at the crystalline surface that lead to morphological control of nanocrystals. The same molecules will be used to direct the formation of ordered arrays in one-, two- and/or three-dimensions via supramolecular assembly of the functionality attached to selected faces. This approach to controlling nanocrystal morphology and assembly addresses many of the existing challenges in this field. For example, the ability to target functionality to specific faces will allow the synthesis of bifunctional nanocrystals that can be targeted to specific tissues as well as deliver a drug. Synthesis will also provide a means of specifically functionalizing symmetry related faces with molecular building blocks designed to promote aggregation in non-close-packed geometries. These aggregates can then be used for the controlled release of drugs.